[ https://issues.apache.org/jira/browse/OAK-3070?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15902812#comment-15902812 ]
Chetan Mehrotra commented on OAK-3070: -------------------------------------- bq. But then we should probably replace the existing index on _deletedOnce anyway with a partial index on _deletedOnce+_modified. That might be tricky as per [Mongo Docs|https://docs.mongodb.com/manual/core/index-sparse/#sparse-compound-indexes] {quote} Sparse compound indexes that only contain ascending/descending index keys will index a document as long as the *document contains at least one of the keys.* {quote} Also see [this|https://jira.mongodb.org/browse/SERVER-2193?focusedCommentId=318100&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-318100] comment. > Use a lower bound in VersionGC query to avoid checking unmodified once > deleted docs > ----------------------------------------------------------------------------------- > > Key: OAK-3070 > URL: https://issues.apache.org/jira/browse/OAK-3070 > Project: Jackrabbit Oak > Issue Type: Improvement > Components: mongomk, rdbmk > Reporter: Chetan Mehrotra > Assignee: Vikas Saurabh > Labels: performance > Attachments: OAK-3070-2.patch, OAK-3070.patch, > OAK-3070-updated.patch, OAK-3070-updated.patch > > > As part of OAK-3062 [~mreutegg] suggested > {quote} > As a further optimization we could also limit the lower bound of the _modified > range. The revision GC does not need to check documents with a _deletedOnce > again if they were not modified after the last successful GC run. If they > didn't change and were considered existing during the last run, then they > must still exist in the current GC run. To make this work, we'd need to > track the last successful revision GC run. > {quote} > Lowest last validated _modified can be possibly saved in settings collection > and reused for next run -- This message was sent by Atlassian JIRA (v6.3.15#6346)